In the structure of a conventional enclosed switchboard arranged side by side, main circuit cables for lead-in and lead-out are connected to individual housings (boards), respectively, as shown in FIG. 17. More specifically, in a conventional unit configuration, a cable lead-in board 81 which leads in cables, a circuit breaker containing board 82 in which circuit breakers and the like are contained, and a cable lead-out board 83 which leads out cables are arranged side by side from the left side of FIG. 17. In this manner, lead-in cables and lead-out cables are individually contained in two different housings, respectively.
Incidentally, there is a case where a box for connecting cables is provided on the upper portion of an enclosed switchboard, and cables are connected in the box.
Furthermore, for example, there is a generally known switchboard which is configured such that a plurality of circuit breakers are arranged up and down in a circuit breaker compartment provided on the front side of the inside of a housing, a main busbar compartment and a cable compartment are provided behind the circuit breaker compartment, one end side of each circuit breaker is connected to a main busbar disposed in the main busbar compartment, and the other end side is connected to a load cable in the cable compartment to be led out to the outside (for example, see Patent Document 1).
Besides, the following technique is disclosed as the configuration of a switchboard which takes into account disaster prevention against fire disaster or the like. For example, in a conventional enclosed switchboard shown in FIG. 6 of Patent Document 2, circuit breakers, cables, devices such as busbars are contained in a circuit breaker compartment, a cable compartment, and a busbar compartment, respectively; and each compartment is partitioned by a grounding metal. Furthermore, in a conventional enclosed switchboard shown in FIG. 1 of Patent Document 2, the enclosed switchboard is divided into three blocks of a cable compartment, a busbar compartment, and a circuit breaker compartment; a partition plate is provided in a boundary between the cable compartment and the busbar compartment; air ducts communicated with other are provided in a boundary between the busbar compartment and the circuit breaker compartment and on the lower portion and the upper portion of the enclosed switchboard; a gradient is formed in the air duct of the upper portion; and a fan is provided in an exit of the air duct. Further, a thermoelectric element is provided at a boundary with the air duct on the upper portion of the cable compartment, the busbar compartment, and the circuit breaker compartment.
By such a configuration, indoor air whose temperature rises during energization is released to the outside with a fan while exchanging heat by the thermoelectric element; and the enclosed switchboard is divided into several blocks to prevent fire spread to other blocks even when a fire disaster occurs.
Furthermore, in other conventional enclosed switchboard disclosed in Patent Document 3, there is a structure in which, in the enclosed switchboard in which a plurality of boards are arranged side by side as shown in FIGS. 18 and 19, two partition plates 90 of grounding metal are provided between the adjacent enclosed switchboards and a fire-retardant plate 88 and a gasket 89 are inserted over the whole surface between the partition plates 90; and thus, heat to adjacent circuit breaker boards is blocked to prevent the spread of a fault in the case of fire disaster in the circuit breaker board.
Besides, as the fixing structure of a conventional switchboard which takes into account seismic adequacy, for example, a fixing device like FIG. 20 is known. FIG. 20A is a perspective view of a floor fixing portion; and FIG. 20B is a side sectional view in which FIG. 20A is seen from an arrow direction b. The configuration is made such that, among frames that constitute a housing of the switchboard, a thick flat plate 92 thicker in thickness than a base portion frame 91 is fixed at a corner portion of the base portion frames 91 by being welded to a right angle portion coming into contact on the same flat surface, a foundation bolt 93 embedded in the floor is made to pass through an attaching hole 92a formed in the thick flat plate 92, and clamping is made by a nut 95 via a washer 94 from the upper side; and thus, the switchboard is fixed to a foundation surface (see Patent Document 4).